Yahoo's biggest challenge in embracing the mobile opportunity is distribution. It's not enough to create great experiences for users, as CEO Marissa Mayer has proposed it do. People must become aware of those services and decide to make room for them in the rhythms of their daily lives.

Reciting a question a Yahoo employee had asked her, Mayer asked rhetorically, "Given that we do not have mobile hardware, a mobile OS, a browser, or a social network, how are we going to compete?"

The sad thing about this is that it's true: Yahoo does not make its own mobile hardware, like Google, Apple, or Amazon. It does not have a mobile OS like Google, Apple, or Microsoft. It does not make a Web browser like Google, Apple, or Microsoft. And it does not have a social network like Google or Facebook.

This is similar to the critique people make of Facebook's mobile strategy, by the way—that it does not have its own hardware, mobile OS, or Web browser. But Yahoo is even worse off.

The positive view Mayer puts on this is that Yahoo's weakness "really allows us to partner," since it does not threaten any of the big players in those core areas. Yahoo has agreed to partner with Facebook, for example, on covering big media events.

But ultimately Yahoo will have to find a strong ally in mobile. The most likely candidate, as we've pointed out, is Apple, since it does not compete in Web services with Yahoo the way Google and Microsoft do.